JavaScript RegExp: R naming conventions

Answer 1

I'm not familiar with R or its naming conventions, but I'll give it a shot:

If you're only trying to verify that the name begins correctly, all you need to do is remove the \. from the character class, leaving you with: /^\.(?!\d)|^[a-z]/i. Otherwise, the . may still be the first character with no restrictions on the remaining ones.

If you want to verify the that entire name is correct, something like this should work:

/^(?:\.(?!\d)|[a-z])[a-z0-9_\.]+$/i